Abstract 12142: Electrolyte Abnormalities and Risk of Sudden Death in the General Population

Abstract

Introduction: Electrolyte abnormalities are a substrate for arrhythmogenesis and could be the trigger for sudden cardiac death (SCD). We sought to determine the potential role of electrolyte abnormalities, irrespective of kidney function, in the occurrence of sudden death in the community. Hypothesis: Electrolyte abnormalities increases the risk for SCD in the community regardless of kidney function. Methods: SCD cases and controls from a large population based study in Northwest US (approx 1 million population, 2002-2014) were included if age ≥18 yrs with creatinine clearance (CrCl) and serum electrolytes available for analysis. For cases, CrCl and electrolytes were required to be measured within 90 days of the SCD event. Demographics and lab results were analyzed using student t-tests and chi-square tests. Multiple logistic regression was used to estimate independent association of risk factors with SCD. Results: We evaluated 483 SCD cases (65.8% male) and 886 controls (66.4% male). Cases were more likely to be older (68.8±14.3 vs 67.2±11.3, p=0.03), of black race (9.8 vs 3.2%, p<0.0001) and with worse CrCl (53.4±31.3 vs. 64.0±24.9 ml/min, p<0.0001). Overall, cases had lower levels of mean Na (137.3±4.2 vs 138.3±3.4 mEq/L, p<0.0001), Ca (9.0±0.7 vs 9.2±0.5 mg/dl, p<0.0001) and Mg (2.0±0.5 vs 2.1±0.4 mg/dl, p=0.007); and higher mean K (4.2±0.6 vs 4.1 ±0.5mEq/L, p=0.0008). Prevalence of hyponatremia (<136mEq/L), hyperkalemia (>5.2mEq/L), hypocalcemia (<8.5 mg/dl) and hypomagnesemia (<1.7 mg/dl) were also higher in cases (27.0 vs 16.2%, p<0.0001; 6.1 vs 1.4%, p<0.0001; 19.7 vs 7.9%, p<0.0001 and 20.4 vs 8.3%, p<0.0001, respectively). Adjusting for age, race and kidney function only hyperkalemia [OR 4.65 (95% CI 1.37-15.81), p=0.01], hypocalcemia [2.94 (1.68-5.13), p=0.0001] and hypomagnesemia [2.52 (1.36-4.66), p=0.003] remained significant, conferring a more than two to five-fold increase in SCD risk. Conclusions: Electrolyte abnormalities remain independently associated with increased risk of SCD in the community, even after adjusting for renal function.